RWD vs AWD
RWD (Rear Wheel Drive) and AWD (All Wheel Drive) are two wheel configurations for automobiles; there are also other configurations aside from these two. The main difference between these two is the number of wheels that are being driven by the engine. In a typical 4-wheeled automobile, all are being driven in an AWD while only the two at the rear are being driven in a RWD.
The main advantage of driving all four wheels over just two is traction. With all wheels pushing the vehicle forward there is less chance of slippage as the force can be equally distributed over all the wheels. In a RWD, the front wheels do nothing, aside from steering of course, and all the torque goes to the rear wheels. More power per wheel increases the chance that friction is lost and slippage begins. There is also the issue of handling. If you try to steer in a RWD when the road is very wet or slick with ice, the front wheel is very likely to start sliding due to loss of friction. An AWD mitigates this problem just like with traction. With the front wheels pulling,, rather than being pushed along, an AWD vehicle is able to move and steer better than a RWD vehicle..
Even in normal conditions, an AWD would still be better than a RWD; cornering in particular. An AWD is able to make tighter corners because the front wheels can steer and pull at the same time; effectively reducing the possibility of understeering or oversteering. If you like to do drifting though, you should go for a RWD rather than an AWD.
The main drawback of an AWD is the added weight and complexity of parts needed to make all the wheels turn. Compared to a RWD, an AWD needs two additional differentials and axles. This is unsprung weight, which could hurt the overall performance of the vehicle. The complexity adds to the cost of the vehicle and difficulty in repairing the vehicle when it breaks down.
Summary:
1. RWD uses the rear wheels to push the vehicles while an AWD uses all the wheels
2. AWD produces better traction than RWD
3. AWD provides better handling in bad weather than RWD
4. AWD is better at cornering than RWD
5. AWD is more complex than RWD